1. Field of the Invention
Disclosed herein are polyblend molding compositions which exhibit smoke evolution levels of less than 360 D.sub.m (Flaming) and UL-94 ratings of at least V-1. The polyblends comprise (A) poly(styrene/acrylonitrile/methylmethacrylate) matrix polymer; (B) polychloroprene rubber which is grafted with monomers of the type used to prepare the matrix; (C) a metal oxide; and (D) smoke suppressants.
2. Description of the Prior Art
Fire retardant polymers based on styrene, acrylonitrile and polychloroprene are well known in the art as is evidenced by U.S. Pat. Nos. 3,830,889, 3,903,037 and 3,929,722. The same art also teaches that these compositions may also contain up to about 25 percent by weight of additional monomers such as methylmethacrylate. These polymers described in these references have good flame retardant properties and fulfill a need in the art. A further need exists to reduce the amount of smoke evolved by these polymers under flaming conditions.